Field-magnet for dynamo-electric machines or electric motors.



PATENTED JUNE 2, 1903'.

R. LUNDELL FIELD MAGNET FOR DYNAMO ELECTRIC MACHINES 0R ELECTRIC MOTORS..

APPLICATION FILED DEC. 26,1902.

no menu.

UNETED STATES Patented June 2, 1903.

PATENT OFFICE.

ROBERT LUNDELL, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 729,879, dated June 2, 1903. Application filed December 26, 1902. Serial No. 136,793. (No model.)

To all whom it may concern.-

Be it known that LROBERT LUNDELL, a citizen of the United States, residing at New York, in the borough of Manhattan, county and State of New York, have made a new and useful Invention in Field-Magnets for Dy.- namo-Electric Machines or Electric Motors, of which the following is a specification.

My invention is directed particularly to improvements upon the field-magnet disclosed in United States Patent No. 695,163, granted to me by the United States Patent Office on the 11th day of March, 1902 and it has for its objects, first, to provide novel means for supporting the pole-pieces of laminated fieldmagnets without drilling or forming unnecessary holes through the laminated yokes' of such machines; second, toprovide such machines with a rigid skeleton frameand a lami nated ring-shaped yoke held in place between the end brackets of the frame, together with novel means of support for the pole-pieces of the field-magnets so arranged that they are held against the inner face of the ring-shaped yoke and that the holding means do not pass through the laminations.

For a full and clear understanding of my invention, such as will enable others skilled in the art to construct and use the "same, reference is had to the accompanying drawings, in which- Figure 1 is an end elevational view of a fieldmagnet embodying my improvem ent, showing the right-hand side thereof in sectional view as taken on the line X X, Fig. 2. Fig. 2 is a side elevational view of the same field-magnet, the portion above the center line being a sectional view taken 011 the line Y Y, Fig. 1. Fig. 3 is a detail end elevational view of one of the pole-pieces, illustrating also the means of support therefor and in a curved broken dotted line the exterior contour of one of the fieldeoils.

Referring now to the drawings in detail, 1 represents the laminated ring-shaped yoke, and 2 2 2 2 laminated field-poles having each a curved surface at its outer end adapted to fit accurately against the corresponding inner curved surface of the laminated yoke.

3 3 represent the end brackets of the fieldmagnet, cast in two parts, the shorter bracket being provided with two pairs of integral arms or projections 4 4 4 4, provided with holes or openings extending therethrough for receiving bolts 6 6 6 6. These brackets are provided with feet 5 5 5 5 and are preferably cast in the formshown, so as to give to them the greatest strength with a minimum supply of material, each cas ting being provided with integral lugs or bosses distributed around its outer circumference, through which are drilled holes for receiving screws 9 9, &c. the function of which is to secure the pole-pieces in place within the inner surface of the ring-shaped yoke.

7 7, &c.,-are cheek-pieces or end plates located on opposite sides of the laminated fieldpoles and having a contour not substantially different from that of the laminations, each being provided with lateral openings for receiving a strong rivet 10, which secures the laminated parts of the core together. Each of said cheek-pieces or end plates is also provided with one or more screw-holes 8 8 for receiving the screws 99.

The parts are'assembled as follows: The laminated ring-shaped'yoke is put in place between the inner faces of the end brackets 3 3 with the arms or projections 4 4 4 4 inclosing and centering the same, after which the bolts 6 6 6 6 are passed therethrough and the nuts at the ends thereof secured firmly in position, thus rigidly binding all of the parts of the frame and the yoke together in substantially the same manner as the like parts were bound, as disclosed in my before-mentioned patent. The completed field-magnet poles, with their field-coils curved to fit "the ring-shaped yoke, are then placed in position with the screw-holes 8 8 in alinement with the corresponding holes for the screws 9 9 in the end brackets 3 3, as clearly indicated in Fig. 2 of the drawings, so that the curved outer faces of the field-magnet poles are brought into good magnetic contact with the corresponding curved inner face ofthe laminated ring-shaped yoke. The field-magnet and frame of a dynamo-electric machine or electric motor when thus put together possesses a rigidity of construction which is very desirable with machines of this type, it being important that all of the'laminated parts shall when in position be substantially as rigid as are the like parts of machines which have solid cylindrical field-magnet yokes and ininade.

tegral pole-pieces.

ing or boring holes through the laminations of the yoke also materially increase the rigidity and reduce the expense of the apparatus.

I do not limit my invention to the especial structural arrangement disclosed in the accompanying drawings; as some of the features thereof might be departed from and still come within the scope of my claims, hereinafter I believe it is broadly new with me to secure the laminated yoke thereof through the agency of means exterior to the laminations of both the yoke and the pol e-pieces, and my claims are generic as to this feature.

Having thus described my invention, what I claim and desire tosecure by Letters Patent of the United States is 1. A dynamo-electric machine or electric motor having a laminated yoke and laminated pole-pieces held in contact therewith by means exterior to the laminations of the yoke.

2. A dynamo-electric machine or electric motor having a laminated yoke and laminated pole-pieces, the latter being provided with cheek-pieces or end plates and means for holding said end plates and the laminations in rigid contact with each other; together with means for securing tlie pole pieces in-contact with the yoke at points exterior to said yoke.

A dynamo-electric machine or electric motor havin a laminated yoke; end brackets The novel means of sup- 2 porting the field-magnet poles without drill-- and bolts for binding the brackets and the yoke together; in combination with a series of laminated field-poles having cheek-pieces or end plates and means for binding the same together so as to constitute each a solid polepiece; together with screws or bolts extending throughthe end brackets into the cheek-pieces or end plates of the pole-pieces, whereby all of said parts are bound firmly together.

4:. A dynamo-electric machine or electric motor having a laminated ring-shaped yoke; two end brackets provided with one or more integral pairs of arms or projections inclosing the laminated yoke and bolts for holding said end brackets and yoke together in one solid mass in combination with one or more pairs of laminated field-poles provided each with a pair of cheek-pieces or end plates rigidly held against the outer faces of the laminations thereof andseeure'd to the end brackets by screws or bolts extending therethrough and into the ch eek-pieces, whereby all of said parts are rigidly bound together so as to constitute in effect an integral structure.

In testiniony whereof I have signed my name to this specification in the presence of two subscri'bin witnesses.

I ROBERT IAUNDELL.

lVitnesses:

O. .LKINTNER, M F KEATING, 

